An example of such fire doors is described in JP Publication of Application No. H7-176587 (Patent Document 1). Patent Document 1 is described using the terms and reference numerals (in parentheses) used in Patent Document 1. In the fire door (1a) of Patent Document 1, an automatically opening and closing door (16), which functions as a door body, has upper spacers (12) provided to an upper portion of the automatically opening and closing door (16), and lower spacers (12) provided to a lower portion of the automatically opening and closing door (16). The upper spacers (12) engage a slide pack (11) so as to be smoothly guided along a lateral direction while preventing their movements along the vertical and fore and aft directions. The lower spacers (12) engage a linear guide (13) so as to be smoothly guided along the lateral direction while preventing their movements along the vertical and fore and aft directions.
With the fire door of Patent Document 1, the fire door is moved from its open position to its closed position to close the opening, when a fire breaks out, to prevent the flames, smoke, and hot air generated by the fire from passing through the opening.